The Feasibility of Enhancing Red Sea Urchin, Strongylocentrotus iranciscanus, Stocks in California: An Analysis of the Options

The California fishery for red sea urchins, Strongylocentrotus franciscanus, has undergone explosive growth in recent years and is approaching full exploitation. Thus, there is considerable interest in enhancing stocks to maintain a high rate of landings. Fishable stocks of red sea urchins in different areas appear to be limited at three stages in their life history: By the availability of larvae, by the survival of newly settled to mid-sized animals, and by the food available to support growth and reproduction of larger animals. Here I review other efforts, notably the extensive Japanese work, to enhance fishable stocks of benthic marine invertebrates, and consider the potential options for red sea urchins at different points of limitation. These include collecting or culturing seed for outplanting, physical habitat improvement measures, improving the food supply, and conservation measures to protect existing stocks until alternate methods are proven and in place. The options are compared in terms of biological feasibility, capital and labor requirements, and potential implications for change in the structure of the fishing industry

Coastal climate reflected in carbon-13/carbon-12 ratio of organic carbon in varved sediment from Santa Barbara basin

A 1844-1987 time-series of carbon stable isotope ratios from dated sedimentary total organic carbon from the center of the Santa Barbara basin is compared with historical climate and oceanographic records. Carbon derived from carbon-13-depleted phytoplankton and carbon-13-enriched kelp appear responsible for a large part of the isotopic variance in sedimentary total organic carbon. El Niño/Southern Oscillation events are recorded by the isotopic response of marine organic carbon in sediments

Sea surface temperature and paleo-El Niño events in Santa Barbara Basin, AD 1841-1941

Like pages of a "natural coastal diary", successive layers of anoxic varved sediment in the central Santa Barbara Basin have been used by paleoceanographers to reconstruct aspects of past coastal climate. This report focuses on the end of the "Little Ice Age" (15th to 19th century) and on the beginning of this century, a period known to encompass extreme climate excursions and weather events in the Santa Barbara Basin and other parts of Southern California. El Niño events are known to disrupt Southern California's coastal ecosystems and to cause anomalous weather conditions, but El Niño events in Southern California before 1990 have been largely undocumented

Compounded Perturbations Yield Ecological Surprises

All species have evolved in the presence of distur-bance, and thus are in a sense matched to the recurrence pattern of the perturbations. Conse-quently, disturbances within the typical range, even at the extreme of that range as defined by large, infrequent disturbances (LIDs), usually result in little long-term change to the system’s fundamental character. We argue that more serious ecological consequences result from compounded perturba-tions within the normative recovery time of the community in question. We consider both physi-cally based disturbance (for example, storm, volca-nic eruption, and forest fire) and biologically based disturbance of populations, such as overharvesting, invasion, and disease, and their interactions. Dis-persal capability and measures of generation time or age to first reproduction of the species of interest seem to be the important metrics for scaling the size and frequency of disturbances among different types of ecosystems. We develop six scenarios that de-scribe communities that have been subjected to multiple perturbations, either simultaneously or at a rate faster than the rate of recovery, and appear to have entered new domains or ‘‘ecological surprises.’’ In some cases, three or more disturbances seem to have been required to initiate the changed state. We argue that in a world of ever-more-pervasive anthro-pogenic impacts on natural communities coupled with the increasing certainty of global change, compounded perturbations and ecological surprises will become more common. Understanding these ecological synergisms will be basic to environmental management decisions of the 21st century. Key words: altered community states; dispersal; multiple disturbances; recovery intervals; scaling disturbances

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The State of the California Current, 1997-1998: Transition to El Niño Conditions

Lynn et al.: The California Current, 1997-1998, CalCOFI Rep., Vol. 39, 1998This report, part of a continuing series of annual reports describing oceanographic conditions in the coastal waters of the Californias, emphasizes the 1997-98 period. The coastal waters of the Californias were strongly influenced by El Niiio conditions beginning late in the summer of 1997 and continuing into the summer of 1998. Timely prediction of the onset of this event made it possible for several research programs to augment their observation programs. We review the pattern of atmospheric forcing and changes in the tropical ocean and note the initial impacts upon the California Current system. Sampling being done by the CalCOFI (California Cooperative Oceanic Fisheries Investigations) program is described, and recent data are summarized and interpreted. Data from several other programs including oceanographic sampling off Baja California and central California, and coastal data from buoys, shore stations, and diving programs in kelp forests are reported. There were large and rapid changes in atmospheric forcing and in the upper ocean temperature and salinity distribution and circulation pattern

The State of the California Current in 1998-1999: Transition to Cool-Water Conditions

Hayward et al.: The California Current, 1998-1999, CalCOFI Rep., Vol. 40, 1999.This report reviews and provides a preliminary interpretation of recent observations made by CalCOFI (California Cooperative Oceanic Fisheries Investigations) and other programs sampling the coastal waters of the Californias. Since this is a continuation of a series of annual reports, the emphasis here is upon observations made during the past 18 months, but longer-term trends must also be considered. The major change in oceanographic structure in the past year was the transition from strong El Niiio conditions in early 1998 to cool-water, La Nilia conditions in early 1999. Ecosystem structure also showed large changes during this period. Phytoplankton abundance during 1998, as indlcated by chlorophyll concentration, was typical of the values seen during the last decade, but it appeared to be increasing in early 1999 in association with the transition to cool-water conditions